This invention relates to dentistry, and more particularly to a placement assembly for the insertion of a dental pin into a preformed bore in a tooth stub.
Dental pins are frequently utilized in dental procedures. The dental pin generally includes a threaded post with an enlarged head. The threaded post is threaded into a preformed bore in a tooth stub with the enlarged head projecting above the surface of the tooth stub. A dental superstructure such as a crown, replacement tooth, or the like, is then secured onto the tooth stub utilizing the enlarged head for retaining the superstructure on the tooth stub. Other purposes for such dental pins are also well known in the field of dentistry.
Various insertion devices are available for threading the dental pin into the preformed bore in the tooth stub. One method involves utilizing a hand driver. Other methods utilize a handpiece connected to an automatic drill head or other rotating mechanism. Because the dental pins are of exceedingly small size, there is frequently included an additional retaining portion for holding the dental pin, and the retaining portion is then manipulated by means of the hand driver or automatic handpiece. A dental tool having one such retaining portion is described in my U.S. Pat. No. 4,255,145, issued on Mar. 10, 1981 for a "Dental Tool Having Severable Sections". In that patent, there is disclosed a dental tool provided with a retaining portion having at least two sections with each section including an individual latching arrangement. The sections are so arranged that they can be separable to conveniently provide a desired length for the dental tool to fit into the operative areas of the patient's mouth.
Although the foregoing insertion systems for dental pins have been useful, extreme care must be extended with such systems to provide appropriate seating of the dental pin in the bore. When utilizing automatic handpieces, there is a tendency of overthreading the dental pin, thereby inserting the pin to a greater depth than the preformed bore. Additional stress is then placed on the tooth stub by such excessive threading. Thus, the tooth stub may crack, or the dental pin may snap, or other dangerous situations can occur. Although the use of the automatic handpiece is convenient, it becomes difficult to adequately control the handpiece in order to provide a desired seating of the dental pin in the preformed bore.
On the other hand, the use of a hand driver to manually insert the dental pin may achieve better control, but is a difficult task both for the patient and for the dentist. The process is slow, requiring excessive strain on the patient who must maintain his position for an extended length of time. It is also a difficult task for the dentist who must operate at a continuous methodical pace driving the dental pin throughout the depth of the preformed bore. Such slow process often causes angular distortions and failure to properly position the dental pin with sufficient accuracy.
Accordingly, while dental pins have found an important role in various dental procedures, there is still needed an adequate placement system for approximately seating the dental pin in the preformed bore of the tooth stub.